You can read the Wikipedia article here: https://en.wikipedia.org/wiki/Gamma-ray_burst https://en.wikipedia.org/wiki/Gamma-ray_burst but to summarize the burst

You can read the Wikipedia article here: https://en.wikipedia.org/wiki/Gamma-ray_burst https://en.wikipedia.org/wiki/Gamma-ray_burst but to summarize the burst is believed to be a 'jet' this forms as part of the explosion of the spinning masses.